Time-shifting for push to talk voice communication systems

CROSS-REFERENCE TO RELATED APPLICATIONS

0001This application is a continuation of pending U.S. application Ser. No. 13/767,780, filed Feb. 14, 2013, and entitled “Time-Shifting For Push To Talk Voice Communication Systems,” which is a continuation of U.S. application Ser. No. 12/336,206 (U.S. Pat. No. 8,401,582), filed Dec. 16, 2008, and entitled “Time-Shifting For Push To Talk Voice Communication Systems.” U.S. application Ser. No. 12/336,206 claims the benefit of priority to U.S. Provisional Patent Application No. 61/044,272 filed Apr. 11, 2008, entitled “Time-Shifting for Voice Communications.” All of the foregoing applications are incorporated herein by reference in their entirety for all purposes.

BACKGROUND

00021. Field of the Invention

0003The present invention relates to telecommunications, and more particularly, to an apparatus for applying time-shifting functionality to voice communications.

00042. Description of Related Art

0005Voice communication systems consist of one of more “channels.” In the case of Push To Talk (PTT) systems, such as tactical radios or PTT over Cellular (PoC), only a single channel is used whenever someone is transmitting. A user cannot transmit while their device is receiving. These systems are said to be “half-duplex”. The alternative is “full-duplex” systems like landline telephones, cellular telephones, or VoIP systems such as Skype or SIP. Each of these full-duplex systems uses two channels, one for voice being received and the other for voice being transmitted. User communication devices generally “connect” these channels, either to a speaker, a microphone, or both, depending on the duplex and current mode of operation.

0006Many full-duplex telephony systems have some sort of message recording facility for unanswered calls such as voicemail. If an incoming call goes unanswered, it is redirected to a voicemail system. When the caller finishes the message, the recipient is alerted and may listen to the message. Various options exist for message delivery beyond dialing into the voicemail system, such as email or “visual voicemail”, but these delivery schemes all require the entire message to be left before the recipient can listen to the message.

0007Many home telephones have answering machine systems that record missed calls. They differ from voicemail in that the caller's voice is often played through a speaker on the answering machine while the message is being recorded. The called party can pick up the phone while the caller is leaving a message. If this occurs with most answering machines, the recording of the message stops while the parties engage in a telephone conversation. With other answering machines, however, the live conversation will be recorded unless the called party manually stops the recording. In either recording situation, there is no way for the called party to review the recorded message until after the recording has stopped. There is no way for the recipient to review any portion of the recorded message other than the current point of the conversation while the conversation is ongoing and is being recorded. Only after the conversation has concluded and the parties have hung up or the recipient has manually stopped the recording can the recipient go back and review the recorded message or conversation.

0008Some more recent call management systems provide a “virtual answering machine”, allowing callers to leave a message in a voicemail system, while giving called users the ability to hear the message as it is being left. The actual answering “machine” is typically a voicemail-style server, operated by the telephony service provider. Virtual answering machine systems differ from standard voice mail systems in that the called party may use either their phone or a computer to listen to messages as they are being left. Similar to an answering machine as described in the preceding paragraph, however, the called party can only listen at the current point of the message as it is being left. There is not way to review previous portions of the message before the message is left in its entirety and the caller hangs up.

0009Certain mobile phone handsets have been equipped with an “answering machine” feature inside the handset itself and that behaves similarly to a landline answering machine as described above. With these answering machines, callers may leave a voice message, which is recorded directly on the phone of the recipient. While the answering machine functionality has been integrated into the phone, all of the limitations of answering machines, as discussed above, are still present.

0010With current PTT systems, incoming audio is played on the device as it is received. If the user does not hear the message, for whatever reason, the message is irretrievably lost. Either the sender must resend the message or the recipient must request the sender to re-transmit message. PTT systems generally do not have any sort of “missed message” recording capability.

0011Other forms of PTT messaging systems exist that are purely message based and are never live. See for example U.S. Pat. No. 7,403,775 and U.S. Publications 2005/0221819 and 2005/0202807.

0012A problem with all the above-mentioned systems is that there is no way for: (i) a recipient of a message to review the message while it is being left; (ii) review received messages at an arbitrary time after receipt in a time-shifted or messaging mode; or (iii) seamlessly transition the exchange of messages between a sender and a recipient between the time-shifted mode and a real-time mode.

SUMMARY OF THE INVENTION

0013A network communication device located on a Push To Talk (PTT) communication network and configured to provide time-shifting capabilities to a user of a PTT communication device. The network communication device includes a receiver configured to progressively receive time-based media. The network communication device also includes a time-shifting buffer for progressively storing the received time based media as the time-based media is received and a time-shifting buffer controller configured to control the rendering of the time-based media at the PTT device. In response to a control signal received from the PTT device of the user, the time-based media is rendered at the PTT communication device either (i) in a near real-time mode as the time-based media is progressively received at the network communication device and progressively transmitted to the PTT device or (ii) at an arbitrary later time after the storage of the time-based media in the time-shifting buffer by retrieving the time-based media from the time-shifting buffer at the arbitrary later time and transmitting the retrieved time-based media to the PTT communication device. In various embodiments, the user of the PTT device is provided a number of rendering options, including play the time-based media, pausing the time-based media as it is being rendered, jump backward to review previous time-based media, jump to the most current time-based media, play the time-based media either faster or slower than it was originally encoded and catch up to live.

BRIEF DESCRIPTION OF THE DRAWINGS

0014The invention may best be understood by reference to the following description taken in conjunction with the accompanying drawings, which illustrate specific embodiments of the present invention.

0015<figref idref="DRAWINGS">FIG. 1</figref> illustrates a block diagram of a Store and Stream (SaS) module (i.e., a time-shifting buffer) of the present invention.

0016<figref idref="DRAWINGS">FIGS. 2A through 2E</figref> are a series of flow diagrams illustrating a store and stream function of the communication and management system of the invention.

0017<figref idref="DRAWINGS">FIG. 3</figref> is a block diagram of the SaS module embedded in a VoIP client in accordance with the present invention.

0018<figref idref="DRAWINGS">FIG. 4</figref> is block diagram of the SaS module embedded in a Push To Talk (PTT) client according to the present invention.

0019<figref idref="DRAWINGS">FIG. 5</figref> is a block diagram of the SaS module embedded in a mobile phone with PPT over cellular capabilities according to the present invention.

0020<figref idref="DRAWINGS">FIG. 6</figref> is a block diagram of the SaS module embedded in a legacy telephone according to the present invention.

0021<figref idref="DRAWINGS">FIG. 7</figref> is a diagram illustrating a full duplex conversation with the SaS module for the participants located on the network between user devices according to the present invention.

0022<figref idref="DRAWINGS">FIG. 8</figref> is a diagram of illustrating a PTT transmission with the SaS module located on the network.

0023It should be noted that like reference numbers refer to like elements in the figures.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

0024The present invention will now be described in detail with reference to various embodiments thereof as illustrated in the accompanying drawings. In the following description, specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without using some of the implementation details set forth herein. It should also be understood that well known operations have not been described in detail in order to not unnecessarily obscure the present invention.

0025In U.S. application Ser. No. 12/028,400, filed on Feb. 8, 2008 and entitled “Telecommunication and Multimedia Management Method and Apparatus,” an improved voice and other media communication and management system and method is disclosed. The system and method provides one or more of the following features and functions: (i) enabling users to participate in multiple conversation types, including live phone calls, conference calls, voice messaging, consecutive or simultaneous communications; (ii) enabling users to review the messages of conversations in either a live mode or a time-shifted mode (voice messaging); (iii) enabling users to seamlessly transition a conversation between a synchronous “live” mode and a time shifted mode; (iv) enabling users to participate in conversations without waiting for a connection to be established with another participant or the network. This attribute allows users to begin conversations, participate in conversations, and review previously received time-shifted messages of conversations even when there is no network available, when the network is of poor quality, or other participants are unavailable; (v) enabling the system to save media payload data at the sender and, after network transmission, saving the media payload data at all receivers; (vi) enabling the system to organize messages by threading them sequentially into semantically meaningful conversations in which each message can be identified and tied to a given participant in a given conversation; (vii) enabling users to manage each conversation with a set of user controlled functions, such as reviewing “live”, pausing or time shifting the conversation until it is convenient to review, replaying in a variety of modes (e.g., playing faster, catching up to live, jump to the head of the conversation) and methods for managing conversations (archiving, tagging, searching, and retrieving from archives); (viii) enabling the system to manage and share presence data with all conversation participants, including online status, intentions with respect to reviewing any given message in either the live or time-shifted mode, current attention to messages, rendering methods, and network conditions between the sender and receiver; (iix) enabling users to manage multiple conversations at the same time, where either (a) one conversation is current and all others are paused; (b) multiple conversations are rendered consecutively, such as but not limited to tactical communications; or (c) multiple conversations are active and simultaneously rendered, such as in a stock exchange or trading floor environment; (ix) enabling users to store all conversations, and if desired, persistently archive them in a tangible medium, providing an asset that can be organized indexed, searched, transcribed, translated and/or reviewed as needed; (x) enabling the system to provide real time call functionality using a best-efforts mode of message delivery at a rate “good enough” for rendering as soon as possible (similar to UDP), and the guaranteed eventual delivery of exact copies of the messages as transmitted by requesting retransmission of any missing or defective data from the originally saved perfect copy (similar to TCP); and (xi) enabling the system to optimize the utilization of network bandwidth by making tradeoffs between timeliness and media quality, using the presence and intentions of the recipient(s) (i.e., to either review the media in real-time or in a time-shifted mode), as well as measures of network latency, network degradation, packet loss or damage, and/or current bandwidth conditions. For more details on the Telecommunication and Multimedia Management Method and Apparatus, see the above-mentioned U.S. application Ser. No. 12/028,400, incorporated by reference herein for all purposes.

0026One of the main components in the aforementioned system is a Store and Stream (SaS) module. With the present invention, one or more SaS module(s) may be provided on end-user communication devices and/or at various nodes or hops on a circuit-based network, such as the Public Switched Telephone Network (PSTN), analog voice networks, cellular networks, Push To Talk (PTT) networks, or any other circuit type based network. One or more SaS module(s) may also be provided on end-user devices and/or nodes of a packet-based network or a VoIP network or other network system designed to replicate the functionality of telephone or PTT radio systems using packets. It should be understood that the term “network” should therefore be broadly construed to include any circuit-based or packet based network and should not be construed as limiting in any way.

0027Time-based media is any media that changes meaningfully with respect to time. Voice or video clips are both considered time-based media because they both substantively change as time passes. By way of comparison, a still photo is generally not considered time-based media because it is static and does not change with the passage of time.

0028In embodiments where the SaS module is embedded in an end-user communication device, such as a mobile or cellular phone, handset, radio, PTT communication device, etc., the SaS module acts as a time-shifting buffer between the existing audio/voice hardware on the device (i.e., a microphone or speaker) and the transmitting and receiving hardware on the device, such as a radio transceiver. Any media either generated at or received at the end-user device is stored in a time-based format in the time-shifting buffer in a time-based format.

0029In embodiments where the SaS module is deployed on a server on the network, in what is hereafter referred to as a network communication device, then the time-shifting buffer functionality is located on the network, between the transmitting and receiving end-user communication devices. Transmissions between the two communication devices are stored in a time-based format in the time-shifting buffer on the network.

0030In yet other embodiments, SaS modules may be provided at both end user communication devices and on the network in one or more network communication devices. With this arrangement, the transmissions are stored both on the SaS enabled end user devices and on the one or more network communication devices on the network.

0031The Store and Stream module persistently stores time-based media in the time-based format as the media is received. With embodiments where the SaS module is located on a network communication device, the time-based media is stored as it is received from one or more end-user communication devices as the one or more end-user communication devices send transmissions back and forth over the network. With embodiments where the SaS module is on the end-user communication device itself, the received media that is stored includes both time-based media created by or otherwise originating at the end-user communication device itself and time-based media received over the network from others who have sent messages. In addition, the PTT transmissions are in the form of asynchronous messages. In other words, the PTT transmissions can be transmitted and received between end-user communication devices without having to wait for a network connection to be established between the parties.

0032With standard full-duplex telephone calls, regardless if over legacy phone systems, cellular, wireless, or VoIP, a number of new functions are provided by the storage of voice as time-based media in the SaS module. Foremost, a user may participate in an ongoing exchange of messages in either (i) a “live” near real-time mode, similar to a conventional phone call where spoken words are sent back and forth between the participants, (ii) a time-shifted mode, where the user hears a message at some point “behind” the live point, along with the ability to catch up to the live point by playing the intervening message or messages faster or directly skipping over messages to arrive at the live point; or (iii) seamlessly transition between the real-time mode and the time-shifted mode.

0033If an incoming message is missed, the SaS module records the message from the sender. By default, missed messages would be in a time-shifted state. As missed messages are received, they are queued in storage for later review by the recipient. Alternatively, if a called party is present when a message is received, the called party may chose to engage in the conversation in the real-time mode or review the message at an arbitrary time later in the time-shifted mode. In addition, since the message is being recorded in the SaS module, the recipient also has the option of reviewing any portion of the message as it is being received with a number of playback controls, described in more detail below.

0034Storing the media at the SaS module provides a number of functions previously not available on communication systems: (i) it enables users to leave a message for another party, even when the sender and/or the recipient has poorly functioning or otherwise unavailable network connectivity; (ii) the recipient has the ability to pause, replay, fast-forward, and catch-up-to-live with an ongoing exchange of messages between two or more parties such as during a conversation; (iii) the ability to retrieve and review previously sent, stored and archived messages; (iii) locally generated messages can be mixed as appropriate to create overlapping messages (generated by the normal overlap of multiple speakers during a conversation); (iv) enables the transcription or translation of voice media into either text or other languages; and (v) it enables users with several rendering options, including reviewing messages faster or slower, for example.

0035When listening to messages at some time after the messages have been received in the time-shifted mode, the SaS module provides the user with the ability to speed up the review of the recorded messages at a rendering rate faster than the rate the messages were originally encoded. This allows for more rapid reviewing of older content and also allows users to “catch up” to the live point of a conversation, seamlessly transitioning from the review of previously received and stored media of the conversation with new media as it is being received, hereafter referred to as “catch-up-to-live”.

0036With half-duplex or Push-To-Talk (PTT) systems, either on a tactical radio style device or using PTT over Cellular, the SaS module provides new functionality, including the ability to communicate in either the real-time mode or time-shifted mode, and the ability to seamlessly transition between the two modes, similar to that described above with regard to full duplex communication systems. In addition, PTT users will have the ability to skip forward and backward on a per-message basis. For each message, the user has the option of implementing all the above-listed playback features (e.g., play faster, play slower, catch up to live, etc.). With a SaS module equipped PTT system, incoming messages may optionally be played as they are being received. All received messages, however, are stored for review at an arbitrary later time defined by the recipient. If a user is reviewing an old message while a new message is received, an indication may be provided. Users have the option of reviewing other messages simultaneously with the arrival of new messages or serializing the review of incoming messages. Users can also replay messages that were missed without asking the sending party to retransmit. Further, the SaS module enables a PTT user to set a “do not disturb” mode of interaction where incoming transmissions that are recorded and queued for recipient are not played through the speaker. The time-indexing, recording, and the rendering of messages in the time-shifted mode can also apply to any locally generated transmissions. In this manner, a PTT user can review their message contributions, in addition to any received messages, of an ongoing conversation.

0037With a SaS module embedded in the device of a sending user, the delay imposed on the user by the network for call setup and “volley” times are reduced. A sending user may begin speaking immediately while the SaS module time-indexes and stores the message as time-based media. As the storage is occurring, the sending device carries out the usual network negotiation and setup processes. When a circuit or network connection is established, the SaS module will send the message from storage starting from the beginning of the message. The typical sequence of a caller waiting for a connection to be established and the phone to ring before speaking is thus eliminated.

0038Referring to <figref idref="DRAWINGS">FIG. 1</figref>, a block diagram of the SaS module <b>24</b> according to one embodiment of the present invention is shown. The main function of the SaS module <b>24</b> is that it acts as a time-shifting buffer for communication devices connected to circuit-based or packet based networks that replicate the functionality of telephone or PTT radio systems such as VoIP. The components of the SaS module <b>24</b> are described in detail below. It should be noted that in the embodiment illustrated in <figref idref="DRAWINGS">FIG. 1</figref>, the SaS module <b>24</b> is intended for use in an end-user communication device. In embodiments where the SaS module is located at a node on the network in a network communication device, some of the functionality illustrated in <figref idref="DRAWINGS">FIG. 1</figref> is not required, as pointed out in the discussion below.

0039The Persistent Infinite Message Buffer (PIMB)

0040The Persistent Infinite Message Buffer or PIMB <b>30</b> stores or records time-based media in a time-indexed format and provides a system for the retrieval of the media. In one embodiment, the media in the PIMB <b>30</b> is arbitrarily persistent, meaning it is available virtually forever or at least until it is purposely deleted or deleted in accordance with a predefined retention policy. This persistence is in comparison to existing jitter buffer technology that discards media as soon as it is rendered. Various retention rates and strategies may be employed to make effective use of storage resources. Many possible implementations exist for the physical storage implementation of the PIMB <b>30</b>, including, but not limited to: ROM, RAM, volatile memory, non-volatile memory, Flash memory, hard drives, optical media, or some combination thereof. In one specific embodiment, the PIMB <b>30</b> may be implemented using a small and relatively fast RAM cache memory coupled with a hard drive for persistent storage. The PIMB <b>30</b> is also “infinite in size, meaning the amount of media that can be stored is not inherently limited. As the physical storage capacity of the PIMB <b>30</b> is exceeded, the media is maintained in secondary or archival storage for later retrieval.

0041In various embodiments, the archival storage may be either local or remote. In embodiments where the SaS module <b>24</b> is a node on a network, the archival storage may be located at the same node or at another node on the network. In embodiments where the SaS module <b>24</b> is located on a end-user communication device, the archival storage may be either local at the device or at a remote location accessible over the network. A predefined criteria or a replacement algorithm, such as least-recently-used, or first-in-last-out, is used to control the actual media stored in the PIMB <b>30</b> or archived at any point in time. The PIMB <b>30</b> further provides the attributes of file system storage and the random access attributes of a database. Any number of conversations or messages, regardless of their duration, may be stored and later retrieved for review.

0042In addition, the meta-data associated with messages, such as its originator and its length, may be also stored in the PIMB <b>30</b>. In alternative embodiments, the media and other data can be stored for a designated period of time (e.g. 30 days). Once the age of the media exceeds the designated period, the media is discarded. In another embodiment, media may be discarded based on the sender and/or the recipient of the message, or the topic of the message. In yet other embodiments, certain media may be marked for transience, meaning the messages will not be stored in the PIMB <b>30</b> beyond the requirements for immediate rendering.

0043The PIMB Writer

0044The PIMB writer <b>28</b> writes data to the PIMB <b>30</b> for two basic purposes. The PIMB writer <b>28</b> writes media into the PIMB <b>30</b> derived from media received from a media-capturing device, such as a microphone or video camera (“Encode Receive”). The PIMB writer <b>28</b> also writes media contained in messages received over the network from others into the PIMB <b>30</b> (“Net Receive”). The Encode Receive and Net Receive functions are described in more detail below.

00451. Encode Receive

0046For capturing locally generated media, the PIMB writer <b>28</b> includes Encoder Receiver <b>28</b><i>a </i>and a Media Storer <b>28</b><i>b</i>. When a User speaks into the microphone for example, the hardware <b>34</b> receives the raw audio signals and provides them to the Encoder Receiver <b>28</b><i>a</i>, which encodes the voice into electrical signals, for example in digital form. The Media Store <b>28</b><i>b </i>time-indexes the digital signals and stores the signals as time-based media in the PIMB <b>30</b>. Other types of time-based media, such as video, is processed and stored in a similar manner. The Encode Receive function is typically implemented only on an end user communication device. In embodiments where the SaS module <b>24</b> is located on the network, the Encode Receive functionality may not be needed or implemented.

00472. Net Receive

0048For storing the media of messages received over the network into the PIMB <b>30</b>, the Net Receive function of PIMB writer <b>28</b> includes a Network Receiver <b>28</b><i>c</i>, a Media Bufferer <b>28</b><i>d</i>, and a Media Storer <b>28</b><i>e</i>. The Network Receiver <b>28</b><i>c </i>receives the time-based media of messages over the network. The Media Bufferer <b>28</b><i>d </i>buffers the incoming signals as necessary. The Media Storer <b>28</b><i>e </i>time-indexes and stores the time-based media in the PIMB <b>30</b>. The Net Receive function would typically be implemented in a SaS module <b>24</b> located on both an end-user communication device and in a network communication device located at a node on the network.

0049The PIMB Reader

0050The PIMB reader <b>26</b> reads data from the PIMB <b>30</b> for two basic purposes. The PIMB reader <b>26</b> accesses the PIMB <b>30</b> when a message is to be rendered (“Render”) for the user. Data is also read from the PIMB <b>30</b> when media is to be transmitted (“Transmit”) over the network. The Render and Transmit functions are described below.

00511. Render

0052For the rendering of messages, the PIMB reader <b>26</b> includes a Media Retriever <b>26</b><i>f</i>, a Media Mixer <b>26</b><i>g </i>and a Media Decoder <b>26</b><i>h</i>. The Media Retriever <b>26</b><i>f </i>retrieves the media selected for rendering from the PIMB <b>30</b>. If the selected media of two or more messages overlap by time-index, the Mixer <b>26</b><i>g </i>mixes the overlapping retrieved media. The Media Decoder <b>26</b><i>h </i>decodes or converts the media (in either mixed or non-mixed form) into signals in a form suitable for the hardware driver <b>34</b>. The hardware <b>34</b> then drives a speaker or video display, creating audio and/or video signals. The Render function is typically implemented only on an end user communication device. In embodiments where the SaS module <b>24</b> is located on the network in a network communication device, the Render functionality may not be needed or implemented.

00532. Transmit

0054To transmit messages over the network, the PIMB Reader <b>26</b> includes a Media Retriever <b>26</b><i>i</i>, and a Transmitter <b>26</b><i>j</i>. The Retriever <b>26</b><i>i </i>selects the media from the PIMB <b>30</b> for transmission and the Transmitter <b>26</b><i>j </i>transmits the selected media. Where the SaS module <b>24</b> is located on an end-user communication device, the selected media may be either media previously stored in the PIMB <b>30</b> or media that is currently being created locally for transmission to a recipient over the network. In various embodiments, the currently created media may be stored in the PIMB either (i) just before transmission; (ii) just after transmission, or (iii) or at substantially the same as the media is transmitted. With all three embodiments, any delays associated with storage and transmission are sufficiently small so that the recipient may perceive a “live” experience if rendering the media in the near real-time mode.

0055With embodiment where the SaS module <b>24</b> is located on a network communication device on the network, the media selected for transmission is media that was either previously stored in the PIMB <b>30</b> or media that is being progressively received from a sender for transmission to a recipient. With the former, the media is typically being retrieved from the PIMB <b>30</b> when the recipient wishes to review a previously received and stored message in the time-shifted mode. With the latter, the recipient is reviewing the transmission in the real-time mode, meaning the network communication device is progressively receiving, progressively storing in the time-indexed format in the PIMB <b>30</b>, and progressively transmitting the message to the recipient as the media is being received.

0056Interface Circuit

0057The interface circuit <b>40</b> is responsible for providing an interface between the SaS module <b>24</b> and the underlying application module of an end-user communication device. For example, with a VoIP client communication device, the interface circuit <b>40</b> provides the interface between the SaS module <b>24</b> and the underlying VoIP application of the device. For a PTT radio, the interface circuit <b>40</b> provides the interface between the SaS module <b>24</b> and the PTT radio application module on the device. With a mobile phone with PTT capabilities over cellular or a standard legacy telephone phone, the interface circuit provides an interface between the PTT and underlying cellular radio module or standard telephone module of the devices respectively. In each case, the underlying application module is the hardware and/or software responsible for implementing the VoIP, PPT, and legacy phone functionality of the end-user communication device. A network communication device with an SaS module <b>24</b> would typically not include an interface circuit <b>40</b>, unless the network communication device implemented some of the functionality described above.

0058Controller

0059A controller <b>46</b> is provided to allow a user to interact or control the operation of time-shifting buffer capabilities of the SaS module <b>24</b> through the controller interface <b>48</b>. Through the controller <b>46</b>, a user can implement a host of functions such as the selection of a message among a plurality of messages or the selection of a number of available rendering options, such as: (i) pausing a live a message, (ii) jump backward to review a previous message or messages, (iii) jump to the head (i.e. “live”) or the most current message among an exchange of messages between participants, (iv) play recorded messages faster, (v) play recorded messages slower, and (vi) catching up to live by reviewing the stored messages of an exchange of messages at a rate faster relative to the rate the voice media was originally encoded and stored and seamlessly merging into the current live message.

0060In embodiments where the SaS module <b>24</b> is provided on an end-user communication device, the controller <b>46</b> is designed to interface with any number of user input control or selection features provided on the end-user communication device itself. Control or selection features, such as a touch screen graphical user interface, touch input controls, knobs, a keyboard, slide bars, etc. may be provided enter rendering and other control commands to the SaS module <b>24</b> through the controller <b>46</b>.

0061In embodiments where the SaS module <b>24</b> is provided at a network communication device, the controller <b>46</b> is configured to receive control signals over the network. For example, a user of an end-user communication device may remotely operate the controller <b>46</b> on the SaS module <b>24</b> on the network through various control functions using Dual-Tone Multi-Frequency tones, Short Message Service (SMS) messages, or some other out-of-band signaling mechanism. With PTT applications for example, the controller <b>46</b> enables a user to remotely interact with the SaS module <b>24</b> to implement a wide variety of new functions. For example, PTT users can control the SaS module <b>24</b> to skip forward and backward on a per-message basis as well as the rendering controls described above within each message (e.g., play faster, play slower, etc.). Incoming messages may still be played as they are received, but all received messages will be stored for later review at an arbitrary later time defined by the receiving user. If a user is reviewing an old message, while a new message is received, an indication or flag may be provided through the controller <b>46</b>. By manipulating the controller <b>46</b>, users have the option of reviewing other messages simultaneously with the arrival of new messages or serializing the review of incoming messages. Users can also replay messages that were missed without asking the sending party to retransmit. In yet another embodiment, a “do not disturb” mode can be set where incoming transmissions are recorded and queued for later review without being immediately played or rendered. The controller <b>46</b> also allows a sender to review their sent messages, in addition to any received messages.

0062Operation Flow Diagrams

0063Referring to <figref idref="DRAWINGS">FIGS. 2A through 2E</figref>, a series of flow diagrams are provided to illustrate the operation of the SaS module <b>24</b> on end-user transmitting and receiving communication devices. <figref idref="DRAWINGS">FIG. 2A</figref> shows the sequence of operation of the SaS module when a user transmits messages to a recipient. <figref idref="DRAWINGS">FIGS. 2B and 2C</figref> illustrate the operation of the PIMB writer <b>28</b> and PIMB Reader <b>26</b> during transmission. <figref idref="DRAWINGS">FIGS. 2D and 2E</figref> illustrate the operation of the PIMB Writer <b>28</b> and PIMB Reader <b>26</b> when the SaS module <b>24</b> receives a message. The flow charts below are described in the context of voice media. It should be understood that the flow charts operate in a similar manner for other types of time-based media, such as video, positional or GPS data, or other sensor data (e.g., temperature, pressure, etc.).

0064In <figref idref="DRAWINGS">FIG. 2A</figref>, a user creates messages to be transmitted by speaking into the microphone of their end-user communication device. With the Encode Receive function, the voice signals of the message are encoded as the user speaks by the PIMB Writer <b>28</b> (box <b>130</b>), which converts the voice into electrical signals and stores the electrical signals in the PIMB <b>30</b> (box <b>132</b>) as Media in a time-indexed format. With the Transmit function, the PIMB Reader <b>26</b> transmits the message to the recipient participant(s) over the network <b>133</b>. At the receiving SaS module <b>24</b>, the Net Receive function of the PIMB Writer <b>28</b> receives the message (box <b>136</b>) and stores the message as time-based media into the PIMB <b>30</b> on the receive SaS module <b>24</b>. The Render function of the PIMB reader <b>26</b> on the receive side renders the time-based media from the PIMB <b>30</b> into a medium suitable for human consumption, such as voice or video. Each of these steps are described in more detail below with respect to <figref idref="DRAWINGS">FIGS. 2B through 2E</figref>.

0065In <figref idref="DRAWINGS">FIG. 2B</figref>, the sequence of the Encoder Receive function performed by the PIMB Writer <b>28</b> (step <b>130</b> of <figref idref="DRAWINGS">FIG. 2A</figref>) is provided in detail. In the initial step <b>130</b>₁, the transmitting user originates the voice signals or a message to be transmitted, by for example, speaking into a microphone. In the next step <b>130</b>₂, the Encode Receiver <b>28</b><i>a </i>progressively encodes the voice signals as they are being created. The Media Storer <b>28</b><i>b </i>associates a time-index with the encoded signals as the person is speaking (step <b>130</b>₃) and then progressively stores the media in the PIMB <b>30</b> (step <b>132</b>₄) in a time-indexed format.

0066In <figref idref="DRAWINGS">FIG. 2C</figref>, the sequence of the Transmit function performed by the PIMB Reader <b>26</b> (step <b>134</b> of <figref idref="DRAWINGS">FIG. 2A</figref>) on the sending SaS module <b>24</b> is provided in detail. In the initial step <b>134</b>₁, the media to be transmitted is selected by the Media Retriever <b>26</b><i>i</i>. If the selected media is the media that is currently being created on the end user device, then the Transmitter <b>26</b><i>j </i>progressively transmits the media in various embodiments either just before, just after or at substantially the same time as the media is stored in the PIMB <b>30</b> by the Encode Receive function. Regardless of the embodiment, the media is transmitted without a perceptible delay. As a result, the recipient(s) may optionally render the media in the real-time mode. Alternatively, the user may select media for transmission over the network from the PIMB <b>30</b> (step <b>134</b>₃) that was previously stored. For example, a user may select an old message and transmit it over the network. In this latter case, the Transmitter <b>26</b><i>j </i>retrieves the media from the PIMB starting at the selected point and progressively transmits the media from storage.

0067In <figref idref="DRAWINGS">FIG. 2D</figref>, the sequence for the Net Receive function (step <b>136</b> of <figref idref="DRAWINGS">FIG. 2A</figref>) of the PIMB Writer <b>28</b> of the receive SaS module <b>24</b> is illustrated. In the initial step <b>136</b>₁, the Network Receiver <b>28</b><i>c </i>progressively receives the time-based media of the message over the network. As necessary the incoming media is buffered by the Media Bufferer <b>28</b><i>d</i>. The Media Storer <b>28</b><i>e </i>progressively associates the time-index for the received media (step <b>136</b>₂) and then progressively stores media in the PIMB <b>30</b> (step <b>136</b>₃) in the time-indexed format.

0068In <figref idref="DRAWINGS">FIG. 2E</figref>, the sequence for the Render function of the PIMB Reader <b>26</b> (box <b>140</b> of <figref idref="DRAWINGS">FIG. 2A</figref>) on the receive SaS module <b>24</b> is illustrated. In the initial step <b>140</b>₁, the media (e.g., a message) at a point in time is selected. The Media Retriever <b>26</b><i>f </i>then progressively retrieves the media from the PIMB <b>30</b> starting at the selected point of time (step <b>140</b>₂). The retrieved time-based media is then progressively mixed by the Media Mixer <b>26</b><i>g </i>if appropriate (step <b>140</b>₃). In the next step, the Decoder <b>26</b><i>h </i>progressively decodes either the mixed or non-mixed media (step <b>140</b>₄) into electrical signals suitable for the hardware driver <b>34</b>, which drives a media-generating device such as a speaker or video display (step <b>140</b>₅) to generate audio or video.

0069In the real-time mode, the media selected for rendering is the media being progressively received. In various embodiments of the Net Receive and Render functions, an incoming message may be time-indexed and stored in the PIMB either just before, just after or at substantially the same time the media is being rendered at the end-user device of the recipient. In either case, the delay associated with storing the media is very small. As a result, the recipient may render the media live in the real-time mode. In the time-shifted mode, the media is selected from a previous point in time, retrieved from the PIMB <b>30</b>, and rendered from the selected point forward.

0070In the context of the present application, the term progressive or progressively is intended to be broadly construed and generally mean the continuous processing of a data stream based on availability of the data. For example as a person speaks, their voice is continuously encoded, stored, and transmitted, so long as the voice media is being created. When the person pauses or stops speaking, there is no voice media to continuously process. But when the person resumes speaking again, the progressive processing and transmission of the voice media resumes. On the receive side, the media is also progressive processed (i.e. stored) in any recipient SaS module, either on the network in a network communication device or at a recipient ender user communication device. Further if a recipient has indicated they would like to review the media in the real-time mode, then any intermediate network communication device will continuously or progressively transmit media to the recipient, so long as the media is available. The recipient end-user communication device also continually renders the media as it is progressively received, so long as the media is available.

0071The flow diagrams <b>2</b>A through <b>2</b>E describe the operation of the SaS module <b>24</b> on an end-user communication device as noted above. The operation of the SaS module <b>24</b> on the network in a network communication device operates essentially the same, except for two notable exceptions. Since media is typically not created or rendered on the network, the Encode Receive (<figref idref="DRAWINGS">FIG. 2B</figref>) or Render (<figref idref="DRAWINGS">FIG. 2E</figref>) functions are typically not implemented. Instead, only the Transmit (<figref idref="DRAWINGS">FIG. 2C</figref>) and Net Receive (<figref idref="DRAWINGS">FIG. 2D</figref>) functions are required.

0072Referring to <figref idref="DRAWINGS">FIG. 3</figref>, a block diagram of the SaS module embedded in a VoIP client in accordance with one embodiment of the present invention is shown. In this disclosure, “VoIP” should be understood as a system that provides full-duplex voice and/or video communication using the IP protocol. Example of such systems includes SIP, RTP, Skype, H.323, MGCP, IAX2, etc. In this embodiment, the VoIP client <b>50</b> includes a network interface <b>52</b> to connect the client <b>50</b> to a network <b>54</b>, a VoIP application module <b>56</b> for providing the VoIP functionality, a speaker <b>57</b>, a microphone <b>58</b>, a VoIP controller <b>60</b>, the SaS module <b>24</b>, and the controller <b>46</b>.

0073The VoIP application module <b>56</b> controls the VoIP functionality of the client <b>50</b> as is well known in the art. The SaS module <b>24</b>, which is provided between the network <b>54</b> and the speaker <b>57</b> and microphone <b>58</b> on the client device <b>50</b>, provides the time shifting buffer and SaS functionality, as described above, directly on the device. The operation of the SaS module <b>24</b> is controlled through the controller <b>46</b>, also as described above. The VoIP controller <b>60</b> controls the standard operation of the VoIP application module <b>56</b>, as is well known in the art, through the SaS module <b>24</b>. The standard VoIP controls for call initiation and management are routed through the SaS module <b>24</b> first before they are sent to the VoIP application module <b>56</b> so that the SaS module <b>24</b> can allocate necessary resources for the activities of the VoIP application. With this arrangement, a user of the device sends VoIP related requests to SaS module <b>24</b>, which in turn, relays them to VoIP application module <b>56</b>.

0074Referring to <figref idref="DRAWINGS">FIG. 4</figref>, a block diagram of the SaS module embedded in a Push To Talk (PTT) client <b>70</b> according another embodiment of the present invention is shown. In this embodiment, the PTT client <b>70</b> includes a radio antenna <b>72</b> to connect the client <b>70</b> to a PTT radio network (not illustrated), a PTT radio application module <b>74</b> for providing the PTT functionality, a speaker <b>76</b>, a microphone <b>78</b>, a PTT radio controller <b>79</b>, the SaS module <b>24</b>, and the controller <b>46</b>.

0075The PTT radio application module <b>74</b> controls the PTT functionality of the client <b>70</b> as is well known in the art. The SaS module <b>24</b>, which is provided between the PTT radio network (not illustrated) through the antenna <b>72</b> and the speaker <b>76</b> and microphone <b>78</b> on the client device <b>70</b>, provides the time shifting buffer and SaS functionality, as described above, directly on the device. The operation of the SaS module <b>24</b> is controlled through controller <b>46</b>, also as described above. The PTT radio controller <b>79</b> controls the standard operation of the PTT radio application module <b>74</b>, as is well known in the art, through the SaS module <b>24</b>.

0076Referring to <figref idref="DRAWINGS">FIG. 5</figref>, a block diagram of the SaS module embedded in a mobile phone with PPT over cellular capabilities according to another embodiment of the present invention is shown. In this embodiment, the mobile phone with PPT over cellular client <b>80</b> includes a radio antenna <b>82</b> to connect the client <b>80</b> to a cellular network (not illustrated), a PTT and cellular radio module <b>84</b> for providing standard cellular and PTT functionality, a speaker <b>86</b>, a microphone <b>88</b>, a cellular phone/PTT controller <b>89</b>, the SaS module <b>24</b>, and the SaS controller <b>46</b>.

0077The PTT and cellular radio module <b>84</b> controls PTT and full-duplex voice functionality of the client <b>80</b> as is well known in the art. The SaS module <b>24</b>, which is provided between the cellular radio network (not illustrated) through the antenna <b>82</b> and the speaker <b>86</b> and microphone <b>88</b> on the client device <b>80</b>, provides the time shifting buffer and SaS functionality, as described above, directly on the device. The operation of the SaS module <b>24</b> is controlled through controller <b>46</b>, also as described above. The cellular phone/PTT radio controller <b>89</b> controls the standard operation of the PTT and cellular radio application module <b>84</b> through the SaS module <b>24</b>.

0078In another embodiment, the SaS module <b>24</b> may be provided on a standard mobile phone without the PTT capability and which operates over a cellular network. Such an embodiment would be very similar to the client <b>80</b> as illustrated in <figref idref="DRAWINGS">FIG. 5</figref>, except the module <b>84</b> and the controller <b>89</b> would not have PTT functionality or PTT controls respectively.

0079Referring to <figref idref="DRAWINGS">FIG. 6</figref>, a block diagram of the SaS module embedded in a legacy telephone according to yet another embodiment of the present invention is shown. In this embodiment, the telephone client <b>90</b> includes a legacy telephone transceiver <b>92</b> to connect the client <b>90</b> to a legacy telephone network (not illustrated), a legacy or standard telephone module <b>94</b> for providing standard telephone functionality, a speaker <b>96</b>, a microphone <b>98</b>, a telephone keypad <b>99</b>, the SaS module <b>24</b>, and the SaS controller <b>46</b>.

0080The legacy telephone module <b>94</b> controls PTT and full-duplex voice functionality of the client <b>90</b> as is well known in the art. The SaS module <b>24</b>, which is provided between the legacy telephone network (not illustrated) through the transceiver <b>92</b> and the speaker <b>96</b> and microphone <b>98</b> on the client device <b>90</b>, provides the time shifting buffer and SaS functionality, as described above, directly on the device. The operation of the SaS module <b>24</b> is controlled through controller <b>46</b>, also as described above. The telephone keypad <b>99</b> controls the standard operation of the legacy telephone module <b>84</b> through the SaS module <b>24</b>.

0081In each of the embodiments described above in <figref idref="DRAWINGS">FIGS. 3 through 6</figref>, the SaS module <b>24</b> is provided on the client. But as previously noted, the SaS module <b>24</b> may be provided on the network, providing legacy land-line phones, mobile phones, PTT radios, and PTT enabled mobile phones with SaS functionality.

0082Referring to <figref idref="DRAWINGS">FIG. 7</figref>, a diagram illustrating a full-duplex conversation where the SaS modules <b>24</b> for the participants are located on the network is shown. In this embodiment, two non-SaS enabled end-user devices A and B are engaged in a full-duplex conversation and two network communication devices <b>100</b>, each including an SaS module <b>24</b>, are provided on the network for user A and B respectively. With this arrangement, media transmitted by user A to user B is transmitted using a first channel. A second channel is used for transmissions from user B to user A. Any transmissions on the first and second channels are stored in the SaS modules <b>24</b> of the two network communication devices <b>100</b> respectively. <figref idref="DRAWINGS">FIG. 8</figref> is a diagram illustrating a half-duplex PTT system with two network communication devices <b>100</b>, each including an SaS module <b>24</b>, for storing the transmissions from end user device A to end user device B (e.g., conventional PTT devices).

0083With the embodiments shown in both <figref idref="DRAWINGS">FIGS. 7 and 8</figref>, user B controls its respective SaS module <b>24</b> through various control functions using DTMF tones, SMS messages, or some other out-of-band signaling mechanism. The controller <b>46</b> of the SaS module <b>24</b> corresponding to user B, in response to the control signals received from the communication device of user B, is configured to control the rendering of the time-based media from user A at the communication device of user B in either the near real-time or time-shifted modes.

0084In the near real-time mode, as the time-based media is progressively received at the SaS module <b>24</b> from the communication device A, it is progressively stored in the PIMB <b>30</b> and progressively transmitted to the communication device B for immediate rendering. As a result, user B has a “real-time” experience when reviewing or rendering the media.

0085On the other hand in the time-shifted mode, the transmission is not immediately rendered at device B as it is being transmitted by device A. For example, if user B is not available, or intentionally wishes not to review a transmission from user A in real-time, then the transmission is received and stored in the PIMB <b>30</b> of the SaS module <b>24</b> corresponding to user B, but is not progressively forwarded to the device of user B. At some later time arbitrary defined by user B, the media of the missed transmission may be reviewed.

0086To review the media in the time-shifted mode, user B generates control signals requesting the message. In response, the SaS module <b>24</b> retrieves the time-based media of the message from the PIMB <b>30</b> and progressively transmits the retrieved time-based media to the communication device of user B for rendering. In addition, user B may further generate a number of control signals to select any number of rendering options besides simply playing the time-based media, such as pausing time-based media as it is being rendered, jump backward to review previous time-based media, jump to the most current time-based media, play the time-based media either faster or slower than it was originally encoded and catch up to live.

0087User B may also seamlessly transition between the near-real-time and time-shifted modes. For example, user B may pause or stop the rendering of a message from user A in the real-time mode. In this situation, user B may subsequently review the message at an arbitrary later time in the time-shifted mode. Alternatively, user B may be reviewing an old message from user A when a new message arrives. If this occurs, user B may stop the review of the old message and immediate transition to the review of the new message as the media arrives in the real-time mode. Alternatively, user B can implement the catch up to live feature, speeding up the rendering of the old media until caught up with the new media as it progressively arrives over the network. In either case, user B seamlessly transitions from the time-shifted mode to the near real-time mode.

0088Although not described in detail herein, user A may review transmissions from user B in either the real-time or time-shifted modes, and with all the same rendering controls, in a similar manner as described above. In an alternative embodiment, a single network communication device <b>100</b> may support both end user devices A and B for the embodiments shown in <figref idref="DRAWINGS">FIG. 7</figref> or <b>8</b> respectively. With this embodiment, although there is only one network communication device <b>100</b>, at least a dedicated PIMB would typically be provided for each user A and B respectively. In yet other embodiments, each communication device <b>100</b> may each support multiple users besides A and B in either a half-duplex or full-duplex arrangement. In either case, again at least a dedicated PIMB would typically be provided the for each user respectively. In situations where SaS modules support multiple users, transmit and receive functions may be shared. But each user would ideally have a separate PIMB or a dedicated portion of a larger PIMB. Also with the embodiments shown in <figref idref="DRAWINGS">FIGS. 7 and 8</figref>, either or both user devices A and B may have their own SaS modules <b>24</b>.

0089Although the above description was generally provided in the context of voice media, it should be understood that all types of time-based media could be processed in a similar manner. SaS modules <b>24</b>, regardless of their location, can process other types of time-based media, such as other audio content besides voice, video, GPS or positional data, or sensor data such as time, temperature, pressure, etc.

0090Although many of the components and processes are described above in the singular for convenience, it will be appreciated by one of skill in the art that multiple components and repeated processes can also be used to practice the techniques of the present invention. Further, while the invention has been particularly shown and described with reference to specific embodiments thereof, it will be understood by those skilled in the art that changes in the form and details of the disclosed embodiments may be made without departing from the spirit or scope of the invention. It is therefore intended that the invention be interpreted to include all variations and equivalents that fall within the true spirit and scope of the present invention.